Question: Every year during hurricane season, the disaster- preparedness experts remind us that hurricane insurance doesn’t cover flood damage. They tell us we can get flood insurance through a federal program that is supposed to make it affordable. I finally decided to take the advice, only to find out that it’s not affordable at all! They wanted nearly $3,000 a year for the premium, and I am nowhere near the water! Please look into this.

Answer: A big reason flood insurance is so expensive on Oahu — even through the National Flood Insurance Program and even for properties away from the ocean, lakes or streams — is that vast swaths of the island have never been analyzed for flood risk. Those unstudied parcels reside in an expensive netherworld known as Zone D, defined in flood insurance rate maps as “an area of undetermined but possible flood hazards.”

Zone D parcels don’t qualify for Preferred Risk Policy (PRP) premiums available in areas that have been studied and confirmed to have minimal flood hazards, such as Zone X. Last year a PRP premium for a residential property in Zone X would have cost about $500 for maximum NFIP coverage, which is $250,000 for the structure and $100,000 for the contents. That level of coverage would have cost nearly six times more in Zone D, in line with your quote.

Carol Tyau-Beam, Hawaii’s coordinator for the National Flood Insurance Program, has highlighted this problem and is encouraging federal and county officials to work together to update the flood insurance rate maps.

On Oahu “the initial flood insurance rate maps were based on data from new hydrologic and hydraulic studies that were completed as early as August 1976 and other existing studies that were even older. The initial maps were primarily focused on riverine and coastal areas of more developed area at the time. The communities where there are a lot of D zones on today’s FIRM are reflective of that historic mapping,” Tyau-Beam said in an email. “Over the past 39 years since the FIRMs were initially adopted by the city, growth and development on Oahu has exploded. Areas that were once cane fields are now fully developed subdivisions. However, since then most of the map revisions are just that, ‘revisions’ to existing study areas. There has not been any major new study of previously undeveloped land that is likely identified as a D flood zone to evaluate the flood risk on populated areas.”

New technology makes it much easier and cheaper to complete the necessary studies. The city and the Federal Emergency Management Agency have a golden opportunity to do so, she said.

“On April 30, FEMA Region IX sent Mayor Caldwell a letter, notifying him of FEMA’s intent to study selected reaches of streams utilizing an engineering modeling methodology called ‘Base Level Engineering (BLE) Analyses’ that could later be used to support detailed flood studies. The BLE is scheduled to be available to the city around the end of June. This may be an opportunity for the city to request FEMA to assess the D zone areas, in hopes of understanding the flood risk and possibly being able to re-designate some of the D zones to an X zone (if warranted),” she said.

Overall, rating flood hazards on previously unstudied parcels is more likely to lower than raise flood insurance premiums on Oahu, according to preliminary data. However, some parcels may be found to have an actual risk, rather than the indeterminate status of Zone D, which would make insurance even more expensive.

We’ll have more on this topic this week. In the meantime you can find out your property’s flood risk zone on a FEMA website, msc.fema.gov/portal/search.

Write to Kokua Line at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email kokualine@staradvertiser.com.